About LockInCS

LockInCS is a free study site for high school computer science courses, starting with AP® Cybersecurity. Written by computer science educators with CCNA and CEH certifications.

How content is checked

• Every page lists the course and exam description (CED) codes it covers and the date it was last reviewed against the CED.
• Terms are used exactly as the College Board writes them.
• Every checkpoint answer is worked out independently before it is published.
• All text, figures, simulations and questions are original. Spotted a mistake? It gets fixed and listed in the patch notes.

Privacy

• No accounts, no sign-up, no ads and no tracking cookies.
• Checkpoint scores and the lock-in timer are stored only in your own browser (local storage). Clearing your browser data removes them. Nothing is sent to us.
• Fonts are served from this site, not from a third party.

License

Content is © LockInCS and licensed under CC BY-NC-ND 4.0: you may share it unchanged, with credit, for non-commercial use. Teachers are welcome to link to any page.

Trademarks

AP® is a trademark registered by the College Board, which is not affiliated with, and does not endorse, this website.